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dc.contributor.authorCaux, M.
dc.contributor.authorMenard, H.
dc.contributor.authorAlSalik, Y. M.
dc.contributor.authorIrvine, J. T. S.
dc.contributor.authorIdriss, H.
dc.identifier.citationCaux , M , Menard , H , AlSalik , Y M , Irvine , J T S & Idriss , H 2019 , ' Photo-catalytic hydrogen production over Au/g-C 3 N 4 : effect of gold particle dispersion and morphology ' , Physical Chemistry Chemical Physics , vol. 21 , no. 29 , pp. 15974-15987 .
dc.identifier.otherPURE: 260483738
dc.identifier.otherPURE UUID: dfc424f6-a45d-4169-835b-636ebeef8fdc
dc.identifier.otherWOS: 000477705800003
dc.identifier.otherWOS: 000477705800003
dc.identifier.otherScopus: 85070018934
dc.identifier.otherORCID: /0000-0002-8394-3359/work/68280753
dc.description.abstractMetal/semiconductor interactions affect electron transfer rates and this is central to photocatalytic hydrogen ion reduction. While this interaction has been studied in great detail on metal oxide semiconductors, not much is known of Au particles on top of polymeric semiconductors. The effects of gold nanoparticle size and dispersion on top of g-C3N4 were studied by core and valence level spectroscopy and transmission electron microscopy in addition to catalytic tests. The as-prepared, non-calcined catalysts displayed Au particles with uniform dimension (mean particle size = 1.8 nm) and multiple electronic states: XPS Au 4f7/2 lines at 84.9 and 87.1 eV (each with a spin–orbit splitting of 3.6–3.7 eV). These particles, which did not show localized surface plasmon resonance (LSPR), before the reaction, doubled in size after the reaction giving a pronounced LSPR at about 550 nm. The effect of the heating environment on these particles (in air or in H2) was further investigated. While heating in H2 gave Au nanoparticles of different shapes, heating under O2 gave exclusively spherical particles. Similar activity towards photocatalytic hydrogen ion reduction under UV excitation was seen in both cases, however. XPS Au 4f analyses indicated that an increase in deposition time, during catalyst preparation, resulted in an increase in the initial fraction of oxidized gold particles, which were easily reduced under hydrogen. The valence band region for Au/gC3N4 was further studied in an effort to compare it to what is already known for Au/metal oxide semiconductors. A shift of over 2 eV for the Au 5d doublets was noticed between reduced and oxidized gold particles with mean particle sizes between 2 and 6 nm, which is consistent with the final state effect. A narrow range of gold loading for optimal catalytic performance was seen, where it seems that a density of one Au particle per 10 × 10 nm2 is the most suitable. Particle size and shape had a minor effect on performance, which may indicate the absence of a plasmonic effect on the reaction rate.
dc.relation.ispartofPhysical Chemistry Chemical Physicsen
dc.rightsCopyright © 2019 The Author(s). Open Access Article. This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.en
dc.subjectQD Chemistryen
dc.titlePhoto-catalytic hydrogen production over Au/g-C3N4 : effect of gold particle dispersion and morphologyen
dc.typeJournal articleen
dc.description.versionPublisher PDFen
dc.contributor.institutionUniversity of St Andrews.School of Chemistryen
dc.contributor.institutionUniversity of St Andrews.Centre for Designer Quantum Materialsen
dc.contributor.institutionUniversity of St Andrews.EaSTCHEMen
dc.description.statusPeer revieweden

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